Desiccant-based cooling system

ABSTRACT

A desiccant-based system and method for conditioning air includes a first unit remotely located from an area whose environment is to be controlled. Additional units are respectively located within areas where air conditioning is desired. Each of the additional units is connected to the first unit such that desiccant can be transferred between each of the additional units and the first unit. Cool, undiluted desiccant can be transferred from the first unit to at least one of the additional units so that ambient air at the location of the additional unit can be dehumidified and cooled. Each of the additional units are separately controllable, such that the respective environments surrounding the additional units can be maintained at different levels of humidity and temperature.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional patentapplication No. 61/527,904 filed 26 Aug. 2011, which is herebyincorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a system and method of desiccant-basedair conditioning.

BACKGROUND

Air conditioning systems may utilize any of a variety of processes forheating, cooling, dehumidifying, and humidifying air. For example, avapor-compression system may take advantage of the expansion andcompression of a refrigerant to provide cooling and/or heat intodifferent ambient spaces. Another type of air conditioning system uses ahygroscopic material, such as a desiccant, to remove or add water to anairstream, and to cool or heat an ambient environment. Examples of suchsystems are described in the following patent: U.S. Pat. No. 6,487,872,issued on 3 Dec. 2002, which is hereby incorporated herein by reference.

Typically desiccant-based systems employ a central unit that uses adesiccant to remove moisture from one airstream, which dilutes thedesiccant, and to give up moisture from the desiccant to anotherairstream, thereby concentrating or regenerating the diluted desiccant.The central unit then provides the conditioned air to an ambientenvironment, which may be, for example, one or more rooms within abuilding.

One limitation of this type of desiccant system is that it may not allowfor individual control of the ambient environment within different roomsin a building. Remotely locating different portions of a desiccantsystem—for example, by having a regenerator outdoors and a processportion indoors—can require a complex system for balancing theconcentration of the desiccant between the regeneration and processactivities. Thus, a need exists for a desiccant-based air conditioningsystem that provides individual control for one or more rooms in abuilding, without an unduly complex system for desiccant balance.

SUMMARY

Embodiments of the present invention provide a system and method forconditioning air using a desiccant-based system that allows individualcontrol of the environment in one or more rooms in a building.

Embodiments of the invention include a system having a first subsystemdisposed outside a building whose environment is to be controlled. Asecond subsystem is located inside the building, in a room where it isdesired to control the environment. The second subsystem is connected tothe first subsystem, such that desiccant is transferred between thefirst and second subsystems as required to provide the desiredenvironment within the room.

Embodiments of the invention also include a desiccant-based airconditioning system having a first subsystem, or outdoor unit, andmultiple second subsystems, or indoor units. Each of the indoor units isconnected to the outdoor unit, such that desiccant can flow to and fromeach of the indoor units individually as required to provide separateenvironmental control for each of the rooms. One way this can beaccomplished is by using a float-actuated valve to control the flow ofdesiccant into the indoor units. A temperature sensor can also beconnected to the valve to provide further control so that flow ofdesiccant into the indoor unit can be a function of both mass andtemperature of the desiccant. In this way, a computer algorithm can beemployed to control the flow of desiccant into and out of the indoorunits individually so that different environmental conditions can bemaintained in the respective spaces where the indoor units are located.

For purposes of cooling and dehumidification, the indoor units willreceive cool, concentrated desiccant from the outdoor unit, which isthen brought into contact with an airflow from the inside space. Theairflow may enter one portion of the indoor unit, where it gives upwater to the desiccant and is simultaneously cooled. The dry, cool airis then exhausted into the ambient environment to provide the desiredconditions.

The diluted desiccant may be gathered in a sump in the indoor unit andtransferred back to the outdoor unit, for example, by gravity or a pumpsystem. The diluted desiccant is regenerated in the outdoor unit, whereit can be exposed to a combination of heat and a relatively dry airflowthat removes water from the desiccant. In some embodiments of theinvention, the heat may be provided through one or more heat exchangersthat are part of a vapor-compression system. The vapor-compressionsystem also includes at least one evaporator, and this can be the sourceof cooling for the desiccant that is provided to the indoor units.

The outdoor unit itself may be divided into separate chambers, a firstof which, a first process chamber, receives the diluted desiccant fromthe indoor units and transfers regenerated desiccant to the indoorunits. The second chamber in the outdoor unit performs the regenerationof the diluted desiccant by adding an airflow and/or heat to remove thewater from the desiccant. The two chambers may be connected, forexample, through an orifice, or some other mechanism effective totransfer the desiccant between the chambers.

In addition to the foregoing, embodiments of the present invention alsoprovide a mechanism for humidifying and warming the indoor air that isprocessed by the indoor units. This can be accomplished, for example, byadding water to the desiccant in the outdoor unit so that desiccantbeing transferred to the indoor units contains a relatively highpercentage of water. Thus, when the indoor air is processed by one ofthe indoor units, it picks up water from the desiccant and exhaustsmoist air back into the indoor environment. This may be particularlyhelpful in the winter in cold climates when the air is generally verydry. In this same way, the desiccant in the outdoor unit can be heatedso that in addition to providing moisture to the indoor air, it warmsthe air as it is processed through the indoor unit.

At least some embodiments of the invention include a system forconditioning air. The system includes a first unit housing a regeneratoroperable to receive a first airflow and bring the first airflow intocontact with a liquid desiccant to transfer water from the liquiddesiccant to the first airflow. The regenerator includes a regeneratorsump for collecting the liquid desiccant after water is transferred tothe liquid desiccant from the first airflow, the first unit furtherhousing a first portion of a process sump fluidly connected to theregenerator sump. A second unit is remotely located from the first unitand is configured to receive a second airflow and bring the secondairflow into contact with the liquid desiccant. The second unit houses asecond portion of the process sump for collecting the liquid desiccantafter it contacts the second airflow. The first unit is in selectivefluid communication with the second unit such that the liquid desiccantcan be selectively transferred between the first and second portions ofthe process sump, and the liquid desiccant transferred from the secondportion of the process sump to the first portion of the process sump canbe admixed with the liquid desiccant in the regenerator sump prior tothe liquid desiccant being returned to the second unit.

At least some embodiments of the invention include a system forconditioning air that includes a first unit remotely located from anindoor space, and a second unit located within the indoor space and inselective fluid communication with the first unit. The first unitincludes a regeneration chamber into which a first airflow is introducedand contacted with a liquid desiccant to transfer water from the liquiddesiccant to the first airflow. The regeneration chamber includes aregenerator sump for collecting the liquid desiccant after water istransferred to the liquid desiccant from the first airflow. The firstunit further includes a first process chamber separated from theregenerator chamber such that the first airflow is inhibited fromentering the first process chamber. The first process chamber includes afirst portion of a process sump fluidly connected to the regeneratorsump. The second unit includes a second process chamber into which asecond airflow is introduced and contacted with the liquid desiccant totransfer water between the second airflow and the liquid desiccant priorto the second airflow being discharged into the indoor space. The secondprocess chamber includes a second portion of the process sump forcollecting the liquid desiccant after it contacts the second airflow.The selective fluid communication between the first and second unitsproviding selective transfer of the liquid desiccant between the firstand second portions of the process sump.

At least some embodiments of the invention include a method forconditioning air that includes bringing a first airflow into contactwith a liquid desiccant in a regeneration chamber to transfer water fromthe liquid desiccant to the first airflow during a first mode ofoperation. The liquid desiccant is collected in a regenerator sump afterwater is transferred from the liquid desiccant to the first airflow. Theliquid desiccant in the regenerator sump is admixed with liquiddesiccant in a first portion of a process sump disposed in a firstprocess chamber adjacent the regeneration chamber. Some of the liquiddesiccant from the first portion of the process sump is transferred to asecond portion of the process sump disposed in a second process chamberlocated remotely from the first process chamber. A second airflow isbrought into contact with the liquid desiccant in the second processchamber to transfer water from the second airflow to the liquiddesiccant during the first mode of operation. The second airflow isexhausted from the second process chamber into an ambient environmenthaving air to be conditioned, after the second airflow has contacted theliquid in the second process chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of an embodiment of the presentinvention having an outdoor unit and three indoor units located inseparate rooms in a building;

FIG. 2 is a schematic representation of an outdoor unit in accordancewith an embodiment of the present invention shown as operational in afirst mode of operation;

FIGS. 3A and 3B respectively show front and side schematic views of anindoor unit in accordance with an embodiment of the present invention;and

FIG. 4 is a schematic representation of an outdoor unit in accordancewith an embodiment of the present invention shown as operational in asecond mode of operation.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The figures are not necessarily to scale; somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention.

FIG. 1 shows a desiccant-based air conditioning system 10 in accordancewith an embodiment of the present invention. The system 10 includes afirst unit, or outdoor unit 12, and three “second units”, or indoorunits 14, 16, 18, remotely located from the outdoor unit 12. Each of theindoor units 14, 16, 18 is located in a respective room 20, 22, 24within a building 26. Although at least some of the indoor units 14, 16,18 appear to be located a relatively long distance from the outdoor unit12, embodiments of the invention may have first and second unitsremotely located from each other, but still within a relatively closedistance of each other. In general, the term “remotely located” refersto the first and second units being at least substantially located inand working on different ambient environments—e.g., an outdoor andindoor environment.

As shown in FIG. 1, a supply line 28 provides desiccant from the outdoorunit 12 to each of the indoor units 14, 16, 18; similarly, a return line30 receives desiccant from each of the indoor units 14, 16, 18 andreturns it to the outdoor unit 12. Although three indoor units are shownin FIG. 1, other embodiments may include more or less than three indoorunits. As used herein, the words “indoor” and “building” generally referto any structure that defines an at least partially enclosed space andseparates it from an ambient outdoor environment. For example, a“building” could be a tent or other temporary, partially enclosedstructure.

FIG. 2 shows a schematic representation of the outdoor unit 12 shown inFIG. 1. The outdoor unit 12 houses a first process chamber 32 wheredesiccant 34 is transferred to and from the indoor units 14, 16, 18. Anydesiccant material effective to produce the desired result may be used,including liquids in the form of pure liquids, solutions, aqueoussolutions, mixtures, and combinations thereof. Lithium chloride (LiCl)and calcium chloride (CaCl₂) are typical of liquid desiccant solutions,but other liquid desiccants may be employed. The outdoor unit 12 alsohouses a regenerator 35, which includes a regeneration chamber 36 wherethe desiccant 34 may be regenerated. In the embodiment shown in FIG. 2,the desiccant 34 transfers between the first process chamber 32 and theregeneration chamber 36 via an aperture, which may be an orifice 38. Inother embodiments, the transfer can be controlled through a float andpump mechanism, or any other method or system effective to transfer thedesiccant as desired. More specifically, the desiccant 34 transfersbetween a first portion of a process sump 42 and a regenerator sump 43,which are separated by a divider 39 having the orifice 38 disposedtherein, which allows diffusion of the desiccant 34 between the sumps42, 43 based on a concentration gradient. As explained in more detailbelow, the indoor units each include a second portion of the processsump, each of which is in selective fluid communication with the firstportion of the process sump 42.

As shown in FIG. 2, the first chamber 32 receives desiccant 34 from theindoor units 14, 16, 18, as indicated by dashed line 40. In thisembodiment, the desiccant 34 is held in the first portion of the processsump 42 at the bottom of the first process chamber 32 housed withinoutdoor unit 12. A first process pump 44 is used to pump the desiccant34 from the first portion of the process sump 42 through a heatexchanger 46 and then to the indoor units, as indicated by the dashedline 48. In the embodiment shown in FIG. 2, the heat exchanger 46 is anevaporator that is part of a refrigeration system, based on avapor-compression cycle, including a compressor 50, a first condenser52, a second condenser 54, and a thermal expansion valve 55. In otherembodiments, a desiccant may be cooled and heated by other sources, suchas a cold water reservoir, solar heat, etc. A bypass valve 57 allowssome of the cooled desiccant 34 to be reintroduced into the firstprocess chamber 32, as indicated by the dashed line 59. The addition ofthe cooled desiccant 34 back into the first portion of the process sump42 effectively allows the sump 42 to retain cooled desiccant 34 and actas a cold liquid storage which can be drawn from when one or more of theindoor units 14, 16, 18 calls for cooling.

The vapor-compression system shown in FIG. 2 may use any fluid, such asa refrigerant, effective to allow the vapor-compression system toselectively heat and cool the desiccant 34 through heat transfer to andfrom the refrigerant. FIG. 2 shows the outdoor unit 12 in a first modeof operation, which may be used effectively in warm, humid conditions.In this mode, heat from the first condenser 52 is transferred to thedesiccant 34 as indicated by the dashed line 56. The desiccant 34 ispumped through the condenser 52 by a regenerator pump 58. After leavingthe condenser 52, the desiccant 34 is sprayed over media 60, which mayinclude one or more porous materials that allow the desiccant 34 to flowthrough them. The second condenser 54 may have associated with it a fan(not shown) for transferring some of the heat from the vapor-compressionsystem into an ambient environment outside of the outdoor unit 12,thereby further cooling the refrigerant prior to the expansion phase ofthe cycle. Although the compressor 50 and condenser 52 are shown withinthe regeneration chamber 36, in other embodiments, they may be locatedoutside of a regeneration chamber and either inside another portion of afirst unit, or outside of the first unit entirely. Having thesecomponents within the regeneration chamber 36 provides additional heatto the regeneration process, thereby helping to evaporate even morewater from the desiccant 34.

As noted above, the desiccant 34 receives heat from the heat exchanger52, and this process helps to regenerate the desiccant 34 by driving offsome of the water that has been picked up by the indoor units 14, 16, 18from the air in their respective indoor spaces 20, 22, 24. In additionto using heat to drive off some of the moisture from the desiccant 34,the outdoor unit 12 also uses an airflow to further remove moisture. Asshown in FIG. 2, a first airflow 62 from an ambient outdoor environmententers the second chamber 36 through an intake 64. The airflow 62 isdrawn in by a fan 66, which moves the air into the second chamber 36,across the desiccant-laden media 60, and out through an exhaust port 68,where the airflow 62 is now shown as 62′, indicating that it is nowmoisture-laden as it leaves the second chamber 36. Because the orifice38 is located below the level of the desiccant in the sumps 42, 43, thefirst process chamber 32 is effectively sealed from any contact with theairflow 62.

FIGS. 3A and 3B respectively show front and side views of one of theindoor units 14 shown in FIG. 1. As shown in FIG. 3A, a valve 70receives desiccant 34 from the outdoor unit 12 as shown by dashed line72, and in particular, it receives the desiccant 34 from the firstportion of the process sump 42. The valve 70 is connected to a floatsystem 74, which indicates the level of the desiccant 34 in a secondportion of the process sump 76 at the bottom of a second process chamber77 housed within the indoor unit 14. Thus, in the embodiment illustratedand described herein, the process side of the system 10 is a splitbetween the outdoor unit 12 and the indoor units 14, 16, 18. Having aportion of the process side located within the same unit that houses theregeneration portion of the system 10 significantly reduces thecomplexity of mass and energy transfer related to balancing thedesiccant 34 between the dilute process side desiccant and the moreconcentrated regenerator side desiccant. Moreover, having anotherportion of the process side housed within the indoor units allows forindividual control over conditioning of the ambient air in differentspaces.

In addition to receiving information regarding the level of thedesiccant 34, the valve 70 also receives information from a temperaturesensor 78, which measures the temperature of the desiccant 34 in thesump 76. The valve 70 may be, for example, a three-way electronicallyactuated solenoid valve, which responds to certain inputs, includinginputs from the float system 74 and the temperature sensor 78. Controlof the valve 70 may be part of a larger control system that alsocoordinates and controls the operation of the various components of theoutdoor unit shown in FIG. 2. Such a control system may contain one ormore algorithms that allow each of the indoor units 14, 16, 18 to beoperated independently of each other to provide for independent controlof the environment in their respective rooms 20, 22, 24.

When the inputs to the valve 70, such as the level of the desiccant 34indicated by the float system 74 and/or the temperature of the desiccant34 as indicated by the temperature sensor 78, indicate that the valve 70should be opened, desiccant from the outdoor unit 12 is provided to theindoor unit 14, as shown by the dashed line 80. In warm, humidenvironments, the desiccant 34 entering the indoor unit 14 from theoutdoor unit 12 will be cool and relatively dry—i.e., undiluted bywater. As explained below, this allows the ambient air in the room 20 tobe dehumidified and cooled to a desired level.

FIG. 3B shows the indoor unit 14 from a side view, and indicates how airflows through and is processed by the unit 14. First, a second airflow86 from an ambient indoor environment enters the indoor unit 14; onceinside, the airflow 86 is brought into contact with the desiccant 34 asit passes over media 84, as indicated by the arrow 88. The flow of airis controlled by a fan 90, which exhausts the second airflow 86 backinto the ambient environment after it has been cooled and dehumidified,now indicated by the label 86′. As the desiccant 34 in the indoor unit14 continues to collect water, the level of the desiccant 34 in the sump76 will rise. In addition, the temperature of the desiccant 34 in thesecond portion of the process sump 76 will increase.

At some point, some of the desiccant 34 will be pumped back into theoutdoor unit as indicated by the dashed line 94 shown in FIG. 3A. Thedesiccant 34 in the indoor unit 14 may flow to the outdoor unit via agravity feed, or it may be pumped. Thus, the apparatus 96 illustratedschematically in FIG. 3A may be, for example, a valve that allows thedesiccant 34 to automatically flow out of the indoor unit 14 when itreaches a certain level. Alternatively, the apparatus 96 may be anelectronically actuated valve, such as the valve 70 described above. Insuch a case, the valve 96 may be opened upon the occurrence of certaininput signals, such as the temperature and/or level of the desiccant 34in the sump 76. Upon returning to the outdoor unit 12, the desiccant 34is regenerated in accordance with the procedures described above.

Because the indoor units 14, 16, 18 are separately controlled and servespaces that may have different requirements, the float system 74 may beactuated frequently in some units, while in other units it is actuatedvery infrequently. In at least some situations, the airflow 86, 86′ mayrecirculate many times through a particular indoor unit before the floatsystem 74 is actuated. This is another advantage of having the processside of a desiccant-based air conditioning system split between theoutdoor unit and the individual indoor units—i.e., transfer of desiccantfrom the indoor units does not need to be based on the concentration ofthe desiccant in the indoor unit sump (although it can be); rather, itcan be based on a temperature or strictly on a volume of liquid in theindoor sump. In this way, the more complex control of balancing theconcentration of the desiccant is handled entirely in the outdoor unit,independent of the indoor units.

The air conditioning described above operates in a first mode ofoperation to cool and dehumidify ambient air inside a room. The system10 can, however, also condition air to have an opposite effect—i.e., thesystem 10 can be operated in a second mode of operation to warm andincrease the humidity of ambient air within a space. One way that thiscan be accomplished is to provide additional water directly to theoutdoor unit 12. This is illustrated in FIG. 4, by the dashed line 98,which shows the addition of water directly to the first portion of theprocess sump, labeled in FIG. 4 as 42′, with the prime symbol (′)indicating like components from the other drawing figures, which showedcomponents of the system 10 in a first mode of operation. Theregenerator 35′ is shut down, and in particular the pump 58′ and fan 66′are not operated, so the addition of the water to the outdoor unit 12directly results in an increased dilution of the desiccant 34 in thesump 42′, and water is not evaporated from the desiccant in theregenerator sump 43′.

In addition to adding water to the desiccant 34, it is also possible toadd heat to the desiccant 34 so that a warm, dilute desiccant can beprovided to the indoor units 14, 16, 18. Heat can be added by any methodeffective to achieve the desired result, such as operating thevapor-compression system in reverse. As shown in FIG. 4, the compressor50′ now pumps refrigerant to the first condenser 52′, which is used toexchange heat with the desiccant 34 being pumped by the first processpump 44′ from the first portion of the process sump 42′ to the indoorunits 14, 16, 18. In this second mode of operation, which may beconsidered in some cases a “winter mode”, the refrigerant can optionallybe pumped through a second condenser 54′, and although not shown in FIG.4, the desiccant 34 can be pumped through both condensers 52′, 54′ topick up additional heat.

Alternatively, the system 10 can be provided with solar collectors thatare either physically attached or remotely operated to provide heatand/or electricity to the system 10. When this process is followed, thewarm, dilute desiccant 34 is passed over the media 84—see FIG. 3A—wheremoisture and heat are collected by the second airflow 86—see FIG.3B—prior to its being exhausted back into the ambient environment.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

What is claimed is:
 1. A system for conditioning air, comprising: afirst unit housing a regenerator operable to receive a first airflow andbring the first airflow into contact with a liquid desiccant to transferwater from the liquid desiccant to the first airflow, the regeneratorincluding a regenerator sump for collecting the liquid desiccant afterwater is transferred to the liquid desiccant from the first airflow, thefirst unit further housing a first portion of a process sump fluidlyconnected to the regenerator sump; and a second unit remotely locatedfrom the first unit and configured to receive a second airflow and bringthe second airflow into contact with the liquid desiccant, the secondunit housing a second portion of the process sump for collecting theliquid desiccant after it contacts the second airflow, the first unitbeing in selective fluid communication with the second unit such thatthe liquid desiccant can be selectively transferred between the firstand second portions of the process sump, and the liquid desiccanttransferred from the second portion of the process sump to the firstportion of the process sump can be admixed with the liquid desiccant inthe regenerator sump prior to the liquid desiccant being returned to thesecond unit.
 2. The system of claim 1, wherein the regenerator sump andthe first portion of the process sump are separated by a divider havingan aperture disposed therein for facilitating diffusion of the liquiddesiccant therebetween.
 3. The system of claim 1, wherein the first unitis located outside a building and is configured to receive and exhaustthe first airflow from and to an ambient outdoor environment, and thesecond unit is located inside the building and is configured to receiveand exhaust the second airflow from and to an ambient environment insidethe building.
 4. The system of claim 1, wherein the first and secondunits are operable in a first mode of operation to transfer water fromthe second airflow to the liquid desiccant, and in a second mode ofoperation to transfer water from the liquid desiccant to the secondairflow, when the second airflow is brought into contact with the liquiddesiccant in the second unit.
 5. The system of claim 4, wherein theregenerator is configured to be shut down during the second mode ofoperation to inhibit evaporation of water from the liquid desiccant inthe regenerator sump.
 6. The system of claim 4, wherein the first unitfurther houses at least a portion of a refrigeration system configuredto selectively heat and cool the liquid desiccant through heat transferwith a refrigerant.
 7. The system of claim 6, wherein the first unithouses at least an evaporator of the refrigeration system, and includesa first process pump configured to pump the liquid desiccant from thefirst portion of the process sump through the evaporator during thefirst mode of operation to transfer heat from the liquid desiccant tothe refrigerant prior to the liquid desiccant being transferred to thesecond unit and brought into contact with the second airflow.
 8. Thesystem of claim 7, further comprising a bypass valve configured toreturn a portion of the liquid desiccant leaving the evaporator to thefirst portion of the process sump prior to the liquid desiccant beingtransferred to the second unit.
 9. The system of claim 6, wherein thefirst unit includes a regenerator pump configured to pump the liquiddesiccant from the regenerator sump through a condenser of therefrigeration system during the first mode of operation to receive heatfrom the refrigerant prior to being brought into contact with the firstairflow.
 10. The system of claim of claim 9, wherein the refrigerationsystem further includes a second condenser configured to further coolthe refrigerant prior to an expansion phase of the refrigerant.
 11. Asystem for conditioning air, comprising: a first unit remotely locatedfrom an indoor space; and a second unit located within the indoor spaceand in selective fluid communication with the first unit, the first unitincluding a regeneration chamber into which a first airflow isintroduced and contacted with a liquid desiccant to transfer water fromthe liquid desiccant to the first airflow, the regeneration chamberincluding a regenerator sump for collecting the liquid desiccant afterwater is transferred to the liquid desiccant from the first airflow, thefirst unit further including a first process chamber separated from theregenerator chamber such that the first airflow is inhibited fromentering the first process chamber, the first process chamber includinga first portion of a process sump fluidly connected to the regeneratorsump, the second unit including a second process chamber into which asecond airflow is introduced and contacted with the liquid desiccant totransfer water between the second airflow and the liquid desiccant priorto the second airflow being discharged into the indoor space, the secondprocess chamber including a second portion of the process sump forcollecting the liquid desiccant after it contacts the second airflow,the selective fluid communication between the first and second unitsproviding selective transfer of the liquid desiccant between the firstand second portions of the process sump.
 12. The system of claim 11,further comprising a plurality of the second units, each located withina respective indoor space and each in selective fluid communication withthe first unit.
 13. The system of claim 11, wherein the regeneratorchamber and the first process chamber are separated by a divider havingan aperture disposed between the regenerator sump and the first portionof the process sump for facilitating diffusion of the liquid desiccanttherebetween.
 14. The system of claim 11, wherein the first and secondunits are operable in a first mode of operation to transfer water fromthe second airflow to the liquid desiccant, and in a second mode ofoperation to transfer water from the liquid desiccant to the secondairflow, when the second airflow is brought into contact with the liquiddesiccant in the second unit.
 15. The system of claim 14, wherein thefirst unit further houses at least a portion of a refrigeration systemconfigured to selectively heat and cool the liquid desiccant throughheat transfer with a refrigerant.
 16. The system of claim 15, whereinthe first unit houses at least an evaporator of the refrigerationsystem, the first process chamber including a first process pumpconfigured to pump the liquid desiccant from the first portion of theprocess sump through the evaporator during the first mode of operationto transfer heat from the liquid desiccant to the refrigerant prior tothe liquid desiccant being transferred to the second unit and broughtinto contact with the second airflow.
 17. The system of claim 16,further comprising a bypass valve configured to return a portion of theliquid desiccant leaving the evaporator to the first portion of theprocess sump prior to the liquid desiccant being transferred to thesecond unit, thereby allowing the first portion of the process sump toretain the cooled desiccant.
 18. The system of claim 17, wherein theregeneration chamber includes a regenerator pump configured to pump theliquid desiccant from the regenerator sump through a condenser of therefrigeration system during the first mode of operation to receive heatfrom the refrigerant prior to being brought into contact with the firstairflow.
 19. A method for conditioning air, comprising: bringing a firstairflow into contact with a liquid desiccant in a regeneration chamberto transfer water from the liquid desiccant to the first airflow duringa first mode of operation; collecting the liquid desiccant in aregenerator sump after water is transferred from the liquid desiccant tothe first airflow; admixing the liquid desiccant in the regenerator sumpwith liquid desiccant in a first portion of a process sump disposed in afirst process chamber adjacent the regeneration chamber; transferringsome of the liquid desiccant from the first portion of the process sumpto a second portion of the process sump disposed in a second processchamber located remotely from the first process chamber; bringing asecond airflow into contact with the liquid desiccant in the secondprocess chamber to transfer water from the second airflow to the liquiddesiccant during the first mode of operation; and exhausting the secondairflow from the second process chamber into an ambient environmenthaving air to be conditioned, after the second airflow has contacted theliquid in the second process chamber.
 20. The method of claim 19,further comprising inhibiting the first airflow from contacting theliquid desiccant in the regeneration chamber during a second mode ofoperation; and bringing a second airflow into contact with the liquiddesiccant in the second process chamber to transfer water from theliquid desiccant to the second airflow during the second mode ofoperation.